Nerve conduction velocity testing has been utilized in evaluation of various conditions such as carpal tunnel syndrome and thoracic outlet compression. Determination of effect of position on conduction velocity in patients with suspected outlet compression may lend invaluable objectivity to the diagnosis of this syndrome that currently is fraught with considerable guesswork.
Ulnar nerves of both forelegs of 12 dogs were isolated. Conduction velocities were determined over measured distances by means of modified electromyography. Responses after varying delay periods in control conditions (no weighted compression), 500-gm and 900-gm compression were determined in 21 forelegs. Average velocities were 39.0, 37.5, and 37.0 meters/sec in the three groups, respectively (P<.01).
This study indicates that positional nerve conduction velocity testing can be helpful in producing objective data for evaluating nerve compression at the thoracic outlet.